//-----------------------------------------------------------------------------
// LEGIC RF simulation code
//-----------------------------------------------------------------------------
-
-#include "proxmark3.h"
-#include "apps.h"
-#include "util.h"
-#include "string.h"
-
#include "legicrf.h"
-#include "legic_prng.h"
-#include "crc.h"
static struct legic_frame {
int bits;
uint32_t data;
} current_frame;
-static crc_t legic_crc;
+static enum {
+ STATE_DISCON,
+ STATE_IV,
+ STATE_CON,
+} legic_state;
+
+static crc_t legic_crc;
+static int legic_read_count;
+static uint32_t legic_prng_bc;
+static uint32_t legic_prng_iv;
+
+static int legic_phase_drift;
+static int legic_frame_drift;
+static int legic_reqresp_drift;
AT91PS_TC timer;
+AT91PS_TC prng_timer;
-static void setup_timer(void)
-{
- /* Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging
- * this it won't be terribly accurate but should be good enough.
- */
+/*
+static void setup_timer(void) {
+ // Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging
+ // this it won't be terribly accurate but should be good enough.
+ //
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
timer = AT91C_BASE_TC1;
timer->TC_CCR = AT91C_TC_CLKDIS;
timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK;
timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
-/* At TIMER_CLOCK3 (MCK/32) */
-#define RWD_TIME_1 150 /* RWD_TIME_PAUSE off, 80us on = 100us */
-#define RWD_TIME_0 90 /* RWD_TIME_PAUSE off, 40us on = 60us */
-#define RWD_TIME_PAUSE 30 /* 20us */
-#define RWD_TIME_FUZZ 20 /* rather generous 13us, since the peak detector + hysteresis fuzz quite a bit */
-#define TAG_TIME_BIT 150 /* 100us for every bit */
-#define TAG_TIME_WAIT 490 /* time from RWD frame end to tag frame start, experimentally determined */
-
+ //
+ // Set up Timer 2 to use for measuring time between frames in
+ // tag simulation mode. Runs 4x faster as Timer 1
+ //
+ AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC2);
+ prng_timer = AT91C_BASE_TC2;
+ prng_timer->TC_CCR = AT91C_TC_CLKDIS;
+ prng_timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV2_CLOCK;
+ prng_timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
}
+ AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
+ AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
+
+ // fast clock
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
+ AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks
+ AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR |
+ AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET;
+ AT91C_BASE_TC0->TC_RA = 1;
+ AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000
+
+*/
+
+// At TIMER_CLOCK3 (MCK/32)
+//#define RWD_TIME_1 150 /* RWD_TIME_PAUSE off, 80us on = 100us */
+//#define RWD_TIME_0 90 /* RWD_TIME_PAUSE off, 40us on = 60us */
+//#define RWD_TIME_PAUSE 30 /* 20us */
+
+// testing calculating in (us) microseconds.
+#define RWD_TIME_1 120 // READER_TIME_PAUSE 20us off, 80us on = 100us 80 * 1.5 == 120ticks
+#define RWD_TIME_0 60 // READER_TIME_PAUSE 20us off, 40us on = 60us 40 * 1.5 == 60ticks
+#define RWD_TIME_PAUSE 30 // 20us == 20 * 1.5 == 30ticks */
+#define TAG_BIT_PERIOD 150 // 100us == 100 * 1.5 == 150ticks
+#define TAG_FRAME_WAIT 495 // 330us from READER frame end to TAG frame start. 330 * 1.5 == 495
+
+#define RWD_TIME_FUZZ 20 // rather generous 13us, since the peak detector + hysteresis fuzz quite a bit
+
+#define SIM_DIVISOR 586 /* prng_time/SIM_DIVISOR count prng needs to be forwared */
+#define SIM_SHIFT 900 /* prng_time+SIM_SHIFT shift of delayed start */
+
+#define OFFSET_LOG 1024
+
#define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz)))
-/* Send a frame in reader mode, the FPGA must have been set up by
- * LegicRfReader
- */
-static void frame_send_rwd(uint32_t data, int bits)
-{
- /* Start clock */
- timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
- while(timer->TC_CV > 1) ; /* Wait till the clock has reset */
+#ifndef SHORT_COIL
+//#define LOW(x) AT91C_BASE_PIOA->PIO_CODR = (x)
+# define SHORT_COIL LOW(GPIO_SSC_DOUT);
+#endif
+#ifndef OPEN_COIL
+//#define HIGH(x) AT91C_BASE_PIOA->PIO_SODR = (x)
+# define OPEN_COIL HIGH(GPIO_SSC_DOUT);
+#endif
+
+uint32_t sendFrameStop = 0;
+
+// Pause pulse, off in 20us / 30ticks,
+// ONE / ZERO bit pulse,
+// one == 80us / 120ticks
+// zero == 40us / 60ticks
+#ifndef COIL_PULSE
+# define COIL_PULSE(x) { \
+ SHORT_COIL; \
+ WaitTicks(RWD_TIME_PAUSE); \
+ OPEN_COIL; \
+ WaitTicks((x)); \
+ }
+#endif
+
+// ToDo: define a meaningful maximum size for auth_table. The bigger this is, the lower will be the available memory for traces.
+// Historically it used to be FREE_BUFFER_SIZE, which was 2744.
+#define LEGIC_CARD_MEMSIZE 1024
+static uint8_t* cardmem;
+static void frame_append_bit(struct legic_frame * const f, int bit) {
+ // Overflow, won't happen
+ if (f->bits >= 31) return;
+
+ f->data |= (bit << f->bits);
+ f->bits++;
+}
+
+static void frame_clean(struct legic_frame * const f) {
+ f->data = 0;
+ f->bits = 0;
+}
+
+// Prng works when waiting in 99.1us cycles.
+// and while sending/receiving in bit frames (100, 60)
+/*static void CalibratePrng( uint32_t time){
+ // Calculate Cycles based on timer 100us
+ uint32_t i = (time - sendFrameStop) / 100 ;
+
+ // substract cycles of finished frames
+ int k = i - legic_prng_count()+1;
+
+ // substract current frame length, rewind to beginning
+ if ( k > 0 )
+ legic_prng_forward(k);
+}
+*/
+
+/* Generate Keystream */
+uint32_t get_key_stream(int skip, int count) {
+ uint32_t key = 0;
int i;
- for(i=0; i<bits; i++) {
- int starttime = timer->TC_CV;
- int pause_end = starttime + RWD_TIME_PAUSE, bit_end;
- int bit = data & 1;
- data = data >> 1;
-
- if(bit ^ legic_prng_get_bit()) {
- bit_end = starttime + RWD_TIME_1;
- } else {
- bit_end = starttime + RWD_TIME_0;
- }
- /* RWD_TIME_PAUSE time off, then some time on, so that the complete bit time is
- * RWD_TIME_x, where x is the bit to be transmitted */
- AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
- while(timer->TC_CV < pause_end) ;
- AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
- legic_prng_forward(1); /* bit duration is longest. use this time to forward the lfsr */
+ // Use int to enlarge timer tc to 32bit
+ legic_prng_bc += prng_timer->TC_CV;
+
+ // reset the prng timer.
+ ResetTimer(prng_timer);
+
+ /* If skip == -1, forward prng time based */
+ if(skip == -1) {
+ i = (legic_prng_bc + SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */
+ i -= legic_prng_count(); /* substract cycles of finished frames */
+ i -= count; /* substract current frame length, rewind to beginning */
+ legic_prng_forward(i);
+ } else {
+ legic_prng_forward(skip);
+ }
+
+ i = (count == 6) ? -1 : legic_read_count;
+
+ /* Write Time Data into LOG */
+ // uint8_t *BigBuf = BigBuf_get_addr();
+ // BigBuf[OFFSET_LOG+128+i] = legic_prng_count();
+ // BigBuf[OFFSET_LOG+256+i*4] = (legic_prng_bc >> 0) & 0xff;
+ // BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff;
+ // BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff;
+ // BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff;
+ // BigBuf[OFFSET_LOG+384+i] = count;
+
+ /* Generate KeyStream */
+ for(i=0; i<count; i++) {
+ key |= legic_prng_get_bit() << i;
+ legic_prng_forward(1);
+ }
+ return key;
+}
+
+/* Send a frame in tag mode, the FPGA must have been set up by
+ * LegicRfSimulate
+ */
+void frame_send_tag(uint16_t response, uint8_t bits, uint8_t crypt) {
+ /* Bitbang the response */
+ LOW(GPIO_SSC_DOUT);
+ AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+ AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
- while(timer->TC_CV < bit_end) ;
+ /* Use time to crypt frame */
+ if(crypt) {
+ legic_prng_forward(2); /* TAG_FRAME_WAIT -> shift by 2 */
+ response ^= legic_prng_get_bits(bits);
}
- {
- /* One final pause to mark the end of the frame */
- int pause_end = timer->TC_CV + RWD_TIME_PAUSE;
- AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
- while(timer->TC_CV < pause_end) ;
- AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
+ /* Wait for the frame start */
+ WaitUS( TAG_FRAME_WAIT );
+
+ uint8_t bit = 0;
+ for(int i = 0; i < bits; i++) {
+
+ bit = response & 1;
+ response >>= 1;
+
+ if (bit)
+ HIGH(GPIO_SSC_DOUT);
+ else
+ LOW(GPIO_SSC_DOUT);
+
+ WaitUS(100);
+ }
+ LOW(GPIO_SSC_DOUT);
+}
+
+/* Send a frame in reader mode, the FPGA must have been set up by
+ * LegicRfReader
+ */
+void frame_sendAsReader(uint32_t data, uint8_t bits){
+
+ uint32_t starttime = GET_TICKS, send = 0;
+ uint16_t mask = 1;
+ uint8_t prng1 = legic_prng_count() ;
+
+ // xor lsfr onto data.
+ send = data ^ legic_prng_get_bits(bits);
+
+ for (; mask < BITMASK(bits); mask <<= 1) {
+ if (send & mask) {
+ COIL_PULSE(RWD_TIME_1);
+ } else {
+ COIL_PULSE(RWD_TIME_0);
+ }
}
- /* Reset the timer, to measure time until the start of the tag frame */
- timer->TC_CCR = AT91C_TC_SWTRG;
- while(timer->TC_CV > 1) ; /* Wait till the clock has reset */
+ // Final pause to mark the end of the frame
+ COIL_PULSE(0);
+
+ sendFrameStop = GET_TICKS;
+ uint8_t cmdbytes[] = {
+ BYTEx(data, 0),
+ BYTEx(data, 1),
+ bits,
+ prng1,
+ legic_prng_count()
+ };
+ LogTrace(cmdbytes, sizeof(cmdbytes), starttime, sendFrameStop, NULL, TRUE);
}
/* Receive a frame from the card in reader emulation mode, the FPGA and
- * timer must have been set up by LegicRfReader and frame_send_rwd.
+ * timer must have been set up by LegicRfReader and frame_sendAsReader.
*
* The LEGIC RF protocol from card to reader does not include explicit
* frame start/stop information or length information. The reader must
* for edges. Count the edges in each bit interval. If they are approximately
* 0 this was a 0-bit, if they are approximately equal to the number of edges
* expected for a 212kHz subcarrier, this was a 1-bit. For timing we use the
- * timer that's still running from frame_send_rwd in order to get a synchronization
+ * timer that's still running from frame_sendAsReader in order to get a synchronization
* with the frame that we just sent.
*
* FIXME: Because we're relying on the hysteresis to just do the right thing
* the range is severely reduced (and you'll probably also need a good antenna).
* So this should be fixed some time in the future for a proper receiver.
*/
-static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt)
-{
- uint32_t the_bit = 1; /* Use a bitmask to save on shifts */
- uint32_t data=0;
- int i, old_level=0, edges=0;
- int next_bit_at = TAG_TIME_WAIT;
-
+static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) {
- if(bits > 16)
- bits = 16;
+ frame_clean(f);
+ if ( bits > 32 ) return;
+
+ uint8_t i = bits, edges = 0;
+ uint16_t lsfr = 0;
+ uint32_t the_bit = 1, next_bit_at = 0, data;
+ int old_level = 0, level = 0;
AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
-
- /* we have some time now, precompute the cipher
- * since we cannot compute it on the fly while reading */
+
+ // calibrate the prng.
legic_prng_forward(2);
+
+ // precompute the cipher
+ uint8_t prng_before = legic_prng_count() ;
- if(crypt)
- {
- for(i=0; i<bits; i++) {
- data |= legic_prng_get_bit() << i;
- legic_prng_forward(1);
- }
- }
-
- while(timer->TC_CV < next_bit_at) ;
+ lsfr = legic_prng_get_bits(bits);
- next_bit_at += TAG_TIME_BIT;
+ data = lsfr;
+
+ //FIXED time between sending frame and now listening frame. 330us
+ //WaitTicks( GET_TICKS - sendFrameStop - TAG_FRAME_WAIT);
+ WaitTicks( 490 );
- for(i=0; i<bits; i++) {
+ uint32_t starttime = GET_TICKS;
+
+ next_bit_at = GET_TICKS + TAG_BIT_PERIOD;
+
+ while ( i-- ){
edges = 0;
+ while ( GET_TICKS < next_bit_at) {
- while(timer->TC_CV < next_bit_at) {
- int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
- if(level != old_level)
- edges++;
+ level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
+
+ if (level != old_level)
+ ++edges;
+
old_level = level;
}
- next_bit_at += TAG_TIME_BIT;
-
- if(edges > 20 && edges < 60) { /* expected are 42 edges */
+ next_bit_at += TAG_BIT_PERIOD;
+
+ // We expect 42 edges == ONE
+ if(edges > 30 && edges < 64)
data ^= the_bit;
- }
- the_bit <<= 1;
+ the_bit <<= 1;
}
+ // output
f->data = data;
f->bits = bits;
-
- /* Reset the timer, to synchronize the next frame */
- timer->TC_CCR = AT91C_TC_SWTRG;
- while(timer->TC_CV > 1) ; /* Wait till the clock has reset */
+
+ // log
+ sendFrameStop = GET_TICKS;
+
+ uint8_t cmdbytes[] = {
+ BYTEx(data,0),
+ BYTEx(data,1),
+ bits,
+ BYTEx(lsfr,0),
+ BYTEx(lsfr,1),
+ BYTEx(data, 0) ^ BYTEx(lsfr,0),
+ BYTEx(data, 1) ^ BYTEx(lsfr,1),
+ prng_before,
+ legic_prng_count()
+ };
+ LogTrace(cmdbytes, sizeof(cmdbytes), starttime, sendFrameStop, NULL, FALSE);
}
-static void frame_clean(struct legic_frame * const f)
-{
- f->data = 0;
- f->bits = 0;
-}
+// Setup pm3 as a Legic Reader
+static uint32_t setup_phase_reader(uint8_t iv) {
+
+ // Switch on carrier and let the tag charge for 1ms
+ HIGH(GPIO_SSC_DOUT);
+ WaitUS(300);
+
+ ResetTicks();
+
+ // no keystream yet
+ legic_prng_init(0);
+
+ // send IV handshake
+ frame_sendAsReader(iv, 7);
-static uint32_t perform_setup_phase_rwd(int iv)
-{
+ // Now both tag and reader has same IV. Prng can start.
+ legic_prng_init(iv);
- /* Switch on carrier and let the tag charge for 1ms */
- AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
- SpinDelay(1);
-
- legic_prng_init(0); /* no keystream yet */
- frame_send_rwd(iv, 7);
- legic_prng_init(iv);
-
- frame_clean(¤t_frame);
- frame_receive_rwd(¤t_frame, 6, 1);
- legic_prng_forward(1); /* we wait anyways */
- while(timer->TC_CV < 387) ; /* ~ 258us */
- frame_send_rwd(0x19, 6);
+ frame_receiveAsReader(¤t_frame, 6);
+ // fixed delay before sending ack.
+ WaitTicks(387); // 244us
+ legic_prng_forward(3); //240us / 100 == 2.4 iterations
+
+ // Send obsfuscated acknowledgment frame.
+ // 0x19 = 0x18 MIM22, 0x01 LSB READCMD
+ // 0x39 = 0x38 MIM256, MIM1024 0x01 LSB READCMD
+ switch ( current_frame.data ) {
+ case 0x0D: frame_sendAsReader(0x19, 6); break;
+ case 0x1D:
+ case 0x3D: frame_sendAsReader(0x39, 6); break;
+ default: break;
+ }
return current_frame.data;
}
static void LegicCommonInit(void) {
- SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
- FpgaSetupSsc();
+
+ FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
+ SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
/* Bitbang the transmitter */
- AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
+ LOW(GPIO_SSC_DOUT);
AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
- setup_timer();
+ // reserve a cardmem, meaning we can use the tracelog function in bigbuff easier.
+ cardmem = BigBuf_malloc(LEGIC_CARD_MEMSIZE);
+ memset(cardmem, 0x00, LEGIC_CARD_MEMSIZE);
+ clear_trace();
+ set_tracing(TRUE);
crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
+
+ StartTicks();
}
-static void switch_off_tag_rwd(void)
-{
- /* Switch off carrier, make sure tag is reset */
- AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
- SpinDelay(10);
-
+// Switch off carrier, make sure tag is reset
+static void switch_off_tag_rwd(void) {
+ LOW(GPIO_SSC_DOUT);
+ WaitUS(200);
WDT_HIT();
+ Dbprintf("Exit Switch_off_tag_rwd");
}
-/* calculate crc for a legic command */
-static int LegicCRC(int byte_index, int value, int cmd_sz) {
- crc_clear(&legic_crc);
+
+// calculate crc4 for a legic READ command
+// 5,8,10 address size.
+static uint32_t legic4Crc(uint8_t legicCmd, uint16_t byte_index, uint8_t value, uint8_t cmd_sz) {
+ crc_clear(&legic_crc);
+ //uint32_t temp = (value << cmd_sz) | (byte_index << 1) | legicCmd;
+ //crc_update(&legic_crc, temp, cmd_sz + 8 );
crc_update(&legic_crc, 1, 1); /* CMD_READ */
crc_update(&legic_crc, byte_index, cmd_sz-1);
crc_update(&legic_crc, value, 8);
}
int legic_read_byte(int byte_index, int cmd_sz) {
- int byte;
- legic_prng_forward(4); /* we wait anyways */
- while(timer->TC_CV < 387) ; /* ~ 258us + 100us*delay */
+ // (us)| ticks
+ // -------------
+ // 330 | 495
+ // 460 | 690
+ // 258 | 387
+ // 244 | 366
+ WaitTicks(332);
+ legic_prng_forward(2); // 460 / 100 = 4.6 iterations
+
+ uint8_t byte = 0, crc = 0, calcCrc = 0;
+ uint32_t cmd = (byte_index << 1) | LEGIC_READ;
- frame_send_rwd(1 | (byte_index << 1), cmd_sz);
- frame_clean(¤t_frame);
+ frame_sendAsReader(cmd, cmd_sz);
+ frame_receiveAsReader(¤t_frame, 12);
- frame_receive_rwd(¤t_frame, 12, 1);
+ byte = BYTEx(current_frame.data, 0);
+ calcCrc = legic4Crc(LEGIC_READ, byte_index, byte, cmd_sz);
+ crc = BYTEx(current_frame.data, 1);
- byte = current_frame.data & 0xff;
- if( LegicCRC(byte_index, byte, cmd_sz) != (current_frame.data >> 8) ) {
- Dbprintf("!!! crc mismatch: expected %x but got %x !!!", LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz), current_frame.data >> 8);
+ if( calcCrc != crc ) {
+ Dbprintf("!!! crc mismatch: expected %x but got %x !!!", calcCrc, crc);
return -1;
}
+
+// legic_prng_forward(2); // 460 / 100 = 4.6 iterations
return byte;
}
-/* legic_write_byte() is not included, however it's trivial to implement
- * and here are some hints on what remains to be done:
- *
- * * assemble a write_cmd_frame with crc and send it
- * * wait until the tag sends back an ACK ('1' bit unencrypted)
- * * forward the prng based on the timing
+/*
+ * - assemble a write_cmd_frame with crc and send it
+ * - wait until the tag sends back an ACK ('1' bit unencrypted)
+ * - forward the prng based on the timing
*/
+//int legic_write_byte(int byte, int addr, int addr_sz, int PrngCorrection) {
+int legic_write_byte(uint8_t byte, uint16_t addr, uint8_t addr_sz) {
+ //do not write UID, CRC at offset 0-4.
+ if (addr <= 4) return 0;
-void LegicRfReader(int offset, int bytes) {
- int byte_index=0, cmd_sz=0, card_sz=0;
+ // crc
+ crc_clear(&legic_crc);
+ crc_update(&legic_crc, 0, 1); /* CMD_WRITE */
+ crc_update(&legic_crc, addr, addr_sz);
+ crc_update(&legic_crc, byte, 8);
+ uint32_t crc = crc_finish(&legic_crc);
+
+ uint32_t crc2 = legic4Crc(LEGIC_WRITE, addr, byte, addr_sz+1);
+ if ( crc != crc2 )
+ Dbprintf("crc is missmatch");
+
+ // send write command
+ uint32_t cmd = ((crc <<(addr_sz+1+8)) //CRC
+ |(byte <<(addr_sz+1)) //Data
+ |(addr <<1) //Address
+ | LEGIC_WRITE); //CMD = Write
+
+ uint32_t cmd_sz = addr_sz+1+8+4; //crc+data+cmd
+
+ legic_prng_forward(2); /* we wait anyways */
+
+ WaitUS(TAG_FRAME_WAIT);
+
+ frame_sendAsReader(cmd, cmd_sz);
+
+ // wllm-rbnt doesnt have these
+ AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
+ AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
+
+ // wait for ack
+ int t, old_level = 0, edges = 0;
+ int next_bit_at = 0;
+
+ WaitUS(TAG_FRAME_WAIT);
+
+ for( t = 0; t < 80; ++t) {
+ edges = 0;
+ next_bit_at += TAG_BIT_PERIOD;
+ while(timer->TC_CV < next_bit_at) {
+ int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
+ if(level != old_level)
+ edges++;
+
+ old_level = level;
+ }
+ if(edges > 20 && edges < 60) { /* expected are 42 edges */
+ int t = timer->TC_CV;
+ int c = t / TAG_BIT_PERIOD;
+
+ ResetTimer(timer);
+ legic_prng_forward(c);
+ return 0;
+ }
+ }
+ ResetTimer(timer);
+ return -1;
+}
+
+int LegicRfReader(int offset, int bytes, int iv) {
+
+ uint16_t byte_index = 0;
+ uint8_t cmd_sz = 0;
+ int card_sz = 0;
+ uint8_t isOK = 1;
+
+ if ( MF_DBGLEVEL >= 2)
+ Dbprintf("setting up legic card, IV = 0x%02x", iv);
+
LegicCommonInit();
- memset(BigBuf, 0, 1024);
+ uint32_t tag_type = setup_phase_reader(iv);
- DbpString("setting up legic card");
- uint32_t tag_type = perform_setup_phase_rwd(0x55);
+ //we lose to mutch time with dprintf
+ switch_off_tag_rwd();
+
switch(tag_type) {
+ case 0x0d:
+ if ( MF_DBGLEVEL >= 2) DbpString("MIM22 card found, reading card");
+ cmd_sz = 6;
+ card_sz = 22;
+ break;
case 0x1d:
- DbpString("MIM 256 card found, reading card ...");
- cmd_sz = 9;
+ if ( MF_DBGLEVEL >= 2) DbpString("MIM256 card found, reading card");
+ cmd_sz = 9;
card_sz = 256;
break;
case 0x3d:
- DbpString("MIM 1024 card found, reading card ...");
- cmd_sz = 11;
+ if ( MF_DBGLEVEL >= 2) DbpString("MIM1024 card found, reading card");
+ cmd_sz = 11;
card_sz = 1024;
break;
default:
- Dbprintf("Unknown card format: %x",tag_type);
- switch_off_tag_rwd();
- return;
+ if ( MF_DBGLEVEL >= 1) Dbprintf("Unknown card format: %x", tag_type);
+ isOK = 0;
+ goto OUT;
+ break;
}
- if(bytes == -1) {
+ if (bytes == -1)
bytes = card_sz;
+
+ if (bytes + offset >= card_sz)
+ bytes = card_sz - offset;
+
+ // Start setup and read bytes.
+ setup_phase_reader(iv);
+
+ LED_B_ON();
+ while (byte_index < bytes) {
+ int r = legic_read_byte(byte_index + offset, cmd_sz);
+
+ if (r == -1 || BUTTON_PRESS()) {
+ if ( MF_DBGLEVEL >= 2) DbpString("operation aborted");
+ isOK = 0;
+ goto OUT;
+ }
+ cardmem[++byte_index] = r;
+ //byte_index++;
+ WDT_HIT();
}
- if(bytes+offset >= card_sz) {
- bytes = card_sz-offset;
- }
- switch_off_tag_rwd(); //we lost to mutch time with dprintf
- perform_setup_phase_rwd(0x55);
+OUT:
+ switch_off_tag_rwd();
+ LEDsoff();
+ uint8_t len = (bytes & 0x3FF);
+ cmd_send(CMD_ACK,isOK,len,0,cardmem,len);
+ return 0;
+}
+
+/*int _LegicRfWriter(int offset, int bytes, int addr_sz, uint8_t *BigBuf, int RoundBruteforceValue) {
+ int byte_index=0;
+
+ LED_B_ON();
+ setup_phase_reader(iv);
+ //legic_prng_forward(2);
+ while(byte_index < bytes) {
+ int r;
+
+ //check if the DCF should be changed
+ if ( (offset == 0x05) && (bytes == 0x02) ) {
+ //write DCF in reverse order (addr 0x06 before 0x05)
+ r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue);
+ //legic_prng_forward(1);
+ if(r == 0) {
+ byte_index++;
+ r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue);
+ }
+ //legic_prng_forward(1);
+ }
+ else {
+ r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz, RoundBruteforceValue);
+ }
+ if((r != 0) || BUTTON_PRESS()) {
+ Dbprintf("operation aborted @ 0x%03.3x", byte_index);
+ switch_off_tag_rwd();
+ LED_B_OFF();
+ LED_C_OFF();
+ return -1;
+ }
+
+ WDT_HIT();
+ byte_index++;
+ if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF();
+ }
+ LED_B_OFF();
+ LED_C_OFF();
+ DbpString("write successful");
+ return 0;
+}*/
+
+void LegicRfWriter(int offset, int bytes, int iv) {
+
+ int byte_index = 0, addr_sz = 0;
+
+ LegicCommonInit();
+
+ if ( MF_DBGLEVEL >= 2) DbpString("setting up legic card");
+
+ uint32_t tag_type = setup_phase_reader(iv);
+
+ switch_off_tag_rwd();
+
+ switch(tag_type) {
+ case 0x0d:
+ if(offset+bytes > 22) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset + bytes);
+ return;
+ }
+ addr_sz = 5;
+ if ( MF_DBGLEVEL >= 2) Dbprintf("MIM22 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset + bytes);
+ break;
+ case 0x1d:
+ if(offset+bytes > 0x100) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset + bytes);
+ return;
+ }
+ addr_sz = 8;
+ if ( MF_DBGLEVEL >= 2) Dbprintf("MIM256 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset + bytes);
+ break;
+ case 0x3d:
+ if(offset+bytes > 0x400) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset + bytes);
+ return;
+ }
+ addr_sz = 10;
+ if ( MF_DBGLEVEL >= 2) Dbprintf("MIM1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset + bytes);
+ break;
+ default:
+ Dbprintf("No or unknown card found, aborting");
+ return;
+ }
+ LED_B_ON();
+ setup_phase_reader(iv);
+ int r = 0;
while(byte_index < bytes) {
- int r = legic_read_byte(byte_index+offset, cmd_sz);
- if(r == -1) {
- Dbprintf("aborting");
- switch_off_tag_rwd();
- return;
+
+ //check if the DCF should be changed
+ if ( ((byte_index+offset) == 0x05) && (bytes >= 0x02) ) {
+ //write DCF in reverse order (addr 0x06 before 0x05)
+ r = legic_write_byte(cardmem[(0x06-byte_index)], (0x06-byte_index), addr_sz);
+
+ // write second byte on success...
+ if(r == 0) {
+ byte_index++;
+ r = legic_write_byte(cardmem[(0x06-byte_index)], (0x06-byte_index), addr_sz);
+ }
+ }
+ else {
+ r = legic_write_byte(cardmem[byte_index+offset], byte_index+offset, addr_sz);
}
- ((uint8_t*)BigBuf)[byte_index] = r;
+
+ if ((r != 0) || BUTTON_PRESS()) {
+ Dbprintf("operation aborted @ 0x%03.3x", byte_index);
+ switch_off_tag_rwd();
+ LEDsoff();
+ return;
+ }
+
+ WDT_HIT();
byte_index++;
}
+ LEDsoff();
+ if ( MF_DBGLEVEL >= 1) DbpString("write successful");
+}
+
+void LegicRfRawWriter(int address, int byte, int iv) {
+
+ int byte_index = 0, addr_sz = 0;
+
+ LegicCommonInit();
+
+ if ( MF_DBGLEVEL >= 2) DbpString("setting up legic card");
+
+ uint32_t tag_type = setup_phase_reader(iv);
+
switch_off_tag_rwd();
- Dbprintf("Card read, use 'hf legic decode' or 'data hexsamples %d' to view results", (bytes+7) & ~7);
+
+ switch(tag_type) {
+ case 0x0d:
+ if(address > 22) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM22", address);
+ return;
+ }
+ addr_sz = 5;
+ if ( MF_DBGLEVEL >= 2) Dbprintf("MIM22 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address, byte);
+ break;
+ case 0x1d:
+ if(address > 0x100) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM256", address);
+ return;
+ }
+ addr_sz = 8;
+ if ( MF_DBGLEVEL >= 2) Dbprintf("MIM256 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address, byte);
+ break;
+ case 0x3d:
+ if(address > 0x400) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM1024", address);
+ return;
+ }
+ addr_sz = 10;
+ if ( MF_DBGLEVEL >= 2) Dbprintf("MIM1024 card found, writing at addr 0x%03.3x - value 0x%03.3x ...", address, byte);
+ break;
+ default:
+ Dbprintf("No or unknown card found, aborting");
+ return;
+ }
+
+ Dbprintf("integer value: %d address: %d addr_sz: %d", byte, address, addr_sz);
+ LED_B_ON();
+
+ setup_phase_reader(iv);
+
+ int r = legic_write_byte(byte, address, addr_sz);
+
+ if((r != 0) || BUTTON_PRESS()) {
+ Dbprintf("operation aborted @ 0x%03.3x (%1d)", byte_index, r);
+ switch_off_tag_rwd();
+ LEDsoff();
+ return;
+ }
+
+ LEDsoff();
+ if ( MF_DBGLEVEL >= 1) DbpString("write successful");
}
+/* Handle (whether to respond) a frame in tag mode
+ * Only called when simulating a tag.
+ */
+static void frame_handle_tag(struct legic_frame const * const f)
+{
+ uint8_t *BigBuf = BigBuf_get_addr();
+
+ /* First Part of Handshake (IV) */
+ if(f->bits == 7) {
+
+ LED_C_ON();
+
+ // Reset prng timer
+ ResetTimer(prng_timer);
+
+ legic_prng_init(f->data);
+ frame_send_tag(0x3d, 6, 1); /* 0x3d^0x26 = 0x1B */
+ legic_state = STATE_IV;
+ legic_read_count = 0;
+ legic_prng_bc = 0;
+ legic_prng_iv = f->data;
+
+
+ ResetTimer(timer);
+ WaitUS(280);
+ return;
+ }
+
+ /* 0x19==??? */
+ if(legic_state == STATE_IV) {
+ int local_key = get_key_stream(3, 6);
+ int xored = 0x39 ^ local_key;
+ if((f->bits == 6) && (f->data == xored)) {
+ legic_state = STATE_CON;
+
+ ResetTimer(timer);
+ WaitUS(200);
+ return;
+
+ } else {
+ legic_state = STATE_DISCON;
+ LED_C_OFF();
+ Dbprintf("iv: %02x frame: %02x key: %02x xored: %02x", legic_prng_iv, f->data, local_key, xored);
+ return;
+ }
+ }
+
+ /* Read */
+ if(f->bits == 11) {
+ if(legic_state == STATE_CON) {
+ int key = get_key_stream(2, 11); //legic_phase_drift, 11);
+ int addr = f->data ^ key; addr = addr >> 1;
+ int data = BigBuf[addr];
+ int hash = legic4Crc(LEGIC_READ, addr, data, 11) << 8;
+ BigBuf[OFFSET_LOG+legic_read_count] = (uint8_t)addr;
+ legic_read_count++;
+
+ //Dbprintf("Data:%03.3x, key:%03.3x, addr: %03.3x, read_c:%u", f->data, key, addr, read_c);
+ legic_prng_forward(legic_reqresp_drift);
+
+ frame_send_tag(hash | data, 12, 1);
+
+ ResetTimer(timer);
+ legic_prng_forward(2);
+ WaitUS(180);
+ return;
+ }
+ }
+
+ /* Write */
+ if(f->bits == 23) {
+ int key = get_key_stream(-1, 23); //legic_frame_drift, 23);
+ int addr = f->data ^ key; addr = addr >> 1; addr = addr & 0x3ff;
+ int data = f->data ^ key; data = data >> 11; data = data & 0xff;
+
+ /* write command */
+ legic_state = STATE_DISCON;
+ LED_C_OFF();
+ Dbprintf("write - addr: %x, data: %x", addr, data);
+ return;
+ }
+
+ if(legic_state != STATE_DISCON) {
+ Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f->bits, f->data, legic_state, legic_read_count);
+ int i;
+ Dbprintf("IV: %03.3x", legic_prng_iv);
+ for(i = 0; i<legic_read_count; i++) {
+ Dbprintf("Read Nb: %u, Addr: %u", i, BigBuf[OFFSET_LOG+i]);
+ }
+
+ for(i = -1; i<legic_read_count; i++) {
+ uint32_t t;
+ t = BigBuf[OFFSET_LOG+256+i*4];
+ t |= BigBuf[OFFSET_LOG+256+i*4+1] << 8;
+ t |= BigBuf[OFFSET_LOG+256+i*4+2] <<16;
+ t |= BigBuf[OFFSET_LOG+256+i*4+3] <<24;
+
+ Dbprintf("Cycles: %u, Frame Length: %u, Time: %u",
+ BigBuf[OFFSET_LOG+128+i],
+ BigBuf[OFFSET_LOG+384+i],
+ t);
+ }
+ }
+ legic_state = STATE_DISCON;
+ legic_read_count = 0;
+ SpinDelay(10);
+ LED_C_OFF();
+ return;
+}
+
+/* Read bit by bit untill full frame is received
+ * Call to process frame end answer
+ */
+static void emit(int bit) {
+
+ switch (bit) {
+ case 1:
+ frame_append_bit(¤t_frame, 1);
+ break;
+ case 0:
+ frame_append_bit(¤t_frame, 0);
+ break;
+ default:
+ if(current_frame.bits <= 4) {
+ frame_clean(¤t_frame);
+ } else {
+ frame_handle_tag(¤t_frame);
+ frame_clean(¤t_frame);
+ }
+ WDT_HIT();
+ break;
+ }
+}
+
+void LegicRfSimulate(int phase, int frame, int reqresp)
+{
+ /* ADC path high-frequency peak detector, FPGA in high-frequency simulator mode,
+ * modulation mode set to 212kHz subcarrier. We are getting the incoming raw
+ * envelope waveform on DIN and should send our response on DOUT.
+ *
+ * The LEGIC RF protocol is pulse-pause-encoding from reader to card, so we'll
+ * measure the time between two rising edges on DIN, and no encoding on the
+ * subcarrier from card to reader, so we'll just shift out our verbatim data
+ * on DOUT, 1 bit is 100us. The time from reader to card frame is still unclear,
+ * seems to be 300us-ish.
+ */
+
+ legic_phase_drift = phase;
+ legic_frame_drift = frame;
+ legic_reqresp_drift = reqresp;
+
+ FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+ SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+ FpgaSetupSsc();
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_212K);
+
+ /* Bitbang the receiver */
+ AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
+ AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
+
+ //setup_timer();
+ crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
+
+ int old_level = 0;
+ int active = 0;
+ legic_state = STATE_DISCON;
+
+ LED_B_ON();
+ DbpString("Starting Legic emulator, press button to end");
+
+ while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+ int level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
+ int time = timer->TC_CV;
+
+ if(level != old_level) {
+ if(level == 1) {
+ timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
+
+ if (FUZZ_EQUAL(time, RWD_TIME_1, RWD_TIME_FUZZ)) {
+ /* 1 bit */
+ emit(1);
+ active = 1;
+ LED_A_ON();
+ } else if (FUZZ_EQUAL(time, RWD_TIME_0, RWD_TIME_FUZZ)) {
+ /* 0 bit */
+ emit(0);
+ active = 1;
+ LED_A_ON();
+ } else if (active) {
+ /* invalid */
+ emit(-1);
+ active = 0;
+ LED_A_OFF();
+ }
+ }
+ }
+
+ /* Frame end */
+ if(time >= (RWD_TIME_1+RWD_TIME_FUZZ) && active) {
+ emit(-1);
+ active = 0;
+ LED_A_OFF();
+ }
+
+ if(time >= (20*RWD_TIME_1) && (timer->TC_SR & AT91C_TC_CLKSTA)) {
+ timer->TC_CCR = AT91C_TC_CLKDIS;
+ }
+
+ old_level = level;
+ WDT_HIT();
+ }
+ if ( MF_DBGLEVEL >= 1) DbpString("Stopped");
+ LEDsoff();
+}
+
+//-----------------------------------------------------------------------------
+// Code up a string of octets at layer 2 (including CRC, we don't generate
+// that here) so that they can be transmitted to the reader. Doesn't transmit
+// them yet, just leaves them ready to send in ToSend[].
+//-----------------------------------------------------------------------------
+// static void CodeLegicAsTag(const uint8_t *cmd, int len)
+// {
+ // int i;
+
+ // ToSendReset();
+
+ // // Transmit a burst of ones, as the initial thing that lets the
+ // // reader get phase sync. This (TR1) must be > 80/fs, per spec,
+ // // but tag that I've tried (a Paypass) exceeds that by a fair bit,
+ // // so I will too.
+ // for(i = 0; i < 20; i++) {
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // }
+
+ // // Send SOF.
+ // for(i = 0; i < 10; i++) {
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // }
+ // for(i = 0; i < 2; i++) {
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // }
+
+ // for(i = 0; i < len; i++) {
+ // int j;
+ // uint8_t b = cmd[i];
+
+ // // Start bit
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+
+ // // Data bits
+ // for(j = 0; j < 8; j++) {
+ // if(b & 1) {
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // } else {
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // }
+ // b >>= 1;
+ // }
+
+ // // Stop bit
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // }
+
+ // // Send EOF.
+ // for(i = 0; i < 10; i++) {
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // ToSendStuffBit(0);
+ // }
+ // for(i = 0; i < 2; i++) {
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // ToSendStuffBit(1);
+ // }
+
+ // // Convert from last byte pos to length
+ // ToSendMax++;
+// }
+
+//-----------------------------------------------------------------------------
+// The software UART that receives commands from the reader, and its state
+// variables.
+//-----------------------------------------------------------------------------
+static struct {
+ enum {
+ STATE_UNSYNCD,
+ STATE_GOT_FALLING_EDGE_OF_SOF,
+ STATE_AWAITING_START_BIT,
+ STATE_RECEIVING_DATA
+ } state;
+ uint16_t shiftReg;
+ int bitCnt;
+ int byteCnt;
+ int byteCntMax;
+ int posCnt;
+ uint8_t *output;
+} Uart;
+
+/* Receive & handle a bit coming from the reader.
+ *
+ * This function is called 4 times per bit (every 2 subcarrier cycles).
+ * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us
+ *
+ * LED handling:
+ * LED A -> ON once we have received the SOF and are expecting the rest.
+ * LED A -> OFF once we have received EOF or are in error state or unsynced
+ *
+ * Returns: true if we received a EOF
+ * false if we are still waiting for some more
+ */
+// static RAMFUNC int HandleLegicUartBit(uint8_t bit)
+// {
+ // switch(Uart.state) {
+ // case STATE_UNSYNCD:
+ // if(!bit) {
+ // // we went low, so this could be the beginning of an SOF
+ // Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
+ // Uart.posCnt = 0;
+ // Uart.bitCnt = 0;
+ // }
+ // break;
+
+ // case STATE_GOT_FALLING_EDGE_OF_SOF:
+ // Uart.posCnt++;
+ // if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
+ // if(bit) {
+ // if(Uart.bitCnt > 9) {
+ // // we've seen enough consecutive
+ // // zeros that it's a valid SOF
+ // Uart.posCnt = 0;
+ // Uart.byteCnt = 0;
+ // Uart.state = STATE_AWAITING_START_BIT;
+ // LED_A_ON(); // Indicate we got a valid SOF
+ // } else {
+ // // didn't stay down long enough
+ // // before going high, error
+ // Uart.state = STATE_UNSYNCD;
+ // }
+ // } else {
+ // // do nothing, keep waiting
+ // }
+ // Uart.bitCnt++;
+ // }
+ // if(Uart.posCnt >= 4) Uart.posCnt = 0;
+ // if(Uart.bitCnt > 12) {
+ // // Give up if we see too many zeros without
+ // // a one, too.
+ // LED_A_OFF();
+ // Uart.state = STATE_UNSYNCD;
+ // }
+ // break;
+
+ // case STATE_AWAITING_START_BIT:
+ // Uart.posCnt++;
+ // if(bit) {
+ // if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
+ // // stayed high for too long between
+ // // characters, error
+ // Uart.state = STATE_UNSYNCD;
+ // }
+ // } else {
+ // // falling edge, this starts the data byte
+ // Uart.posCnt = 0;
+ // Uart.bitCnt = 0;
+ // Uart.shiftReg = 0;
+ // Uart.state = STATE_RECEIVING_DATA;
+ // }
+ // break;
+
+ // case STATE_RECEIVING_DATA:
+ // Uart.posCnt++;
+ // if(Uart.posCnt == 2) {
+ // // time to sample a bit
+ // Uart.shiftReg >>= 1;
+ // if(bit) {
+ // Uart.shiftReg |= 0x200;
+ // }
+ // Uart.bitCnt++;
+ // }
+ // if(Uart.posCnt >= 4) {
+ // Uart.posCnt = 0;
+ // }
+ // if(Uart.bitCnt == 10) {
+ // if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
+ // {
+ // // this is a data byte, with correct
+ // // start and stop bits
+ // Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
+ // Uart.byteCnt++;
+
+ // if(Uart.byteCnt >= Uart.byteCntMax) {
+ // // Buffer overflowed, give up
+ // LED_A_OFF();
+ // Uart.state = STATE_UNSYNCD;
+ // } else {
+ // // so get the next byte now
+ // Uart.posCnt = 0;
+ // Uart.state = STATE_AWAITING_START_BIT;
+ // }
+ // } else if (Uart.shiftReg == 0x000) {
+ // // this is an EOF byte
+ // LED_A_OFF(); // Finished receiving
+ // Uart.state = STATE_UNSYNCD;
+ // if (Uart.byteCnt != 0) {
+ // return TRUE;
+ // }
+ // } else {
+ // // this is an error
+ // LED_A_OFF();
+ // Uart.state = STATE_UNSYNCD;
+ // }
+ // }
+ // break;
+
+ // default:
+ // LED_A_OFF();
+ // Uart.state = STATE_UNSYNCD;
+ // break;
+ // }
+
+ // return FALSE;
+// }
+
+
+static void UartReset() {
+ Uart.byteCntMax = 3;
+ Uart.state = STATE_UNSYNCD;
+ Uart.byteCnt = 0;
+ Uart.bitCnt = 0;
+ Uart.posCnt = 0;
+ memset(Uart.output, 0x00, 3);
+}
+
+// static void UartInit(uint8_t *data) {
+ // Uart.output = data;
+ // UartReset();
+// }
+
+//=============================================================================
+// An LEGIC reader. We take layer two commands, code them
+// appropriately, and then send them to the tag. We then listen for the
+// tag's response, which we leave in the buffer to be demodulated on the
+// PC side.
+//=============================================================================
+
+static struct {
+ enum {
+ DEMOD_UNSYNCD,
+ DEMOD_PHASE_REF_TRAINING,
+ DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
+ DEMOD_GOT_FALLING_EDGE_OF_SOF,
+ DEMOD_AWAITING_START_BIT,
+ DEMOD_RECEIVING_DATA
+ } state;
+ int bitCount;
+ int posCount;
+ int thisBit;
+ uint16_t shiftReg;
+ uint8_t *output;
+ int len;
+ int sumI;
+ int sumQ;
+} Demod;
+
+/*
+ * Handles reception of a bit from the tag
+ *
+ * This function is called 2 times per bit (every 4 subcarrier cycles).
+ * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us
+ *
+ * LED handling:
+ * LED C -> ON once we have received the SOF and are expecting the rest.
+ * LED C -> OFF once we have received EOF or are unsynced
+ *
+ * Returns: true if we received a EOF
+ * false if we are still waiting for some more
+ *
+ */
+
+ #ifndef SUBCARRIER_DETECT_THRESHOLD
+ # define SUBCARRIER_DETECT_THRESHOLD 8
+ #endif
+
+ // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
+#ifndef CHECK_FOR_SUBCARRIER
+# define CHECK_FOR_SUBCARRIER() { v = MAX(ai, aq) + MIN(halfci, halfcq); }
+#endif
+
+// The soft decision on the bit uses an estimate of just the
+// quadrant of the reference angle, not the exact angle.
+// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
+#define MAKE_SOFT_DECISION() { \
+ if(Demod.sumI > 0) \
+ v = ci; \
+ else \
+ v = -ci; \
+ \
+ if(Demod.sumQ > 0) \
+ v += cq; \
+ else \
+ v -= cq; \
+ \
+ }
+
+static RAMFUNC int HandleLegicSamplesDemod(int ci, int cq)
+{
+ int v = 0;
+ int ai = ABS(ci);
+ int aq = ABS(cq);
+ int halfci = (ai >> 1);
+ int halfcq = (aq >> 1);
+
+ switch(Demod.state) {
+ case DEMOD_UNSYNCD:
+
+ CHECK_FOR_SUBCARRIER()
+
+ if(v > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected
+ Demod.state = DEMOD_PHASE_REF_TRAINING;
+ Demod.sumI = ci;
+ Demod.sumQ = cq;
+ Demod.posCount = 1;
+ }
+ break;
+
+ case DEMOD_PHASE_REF_TRAINING:
+ if(Demod.posCount < 8) {
+
+ CHECK_FOR_SUBCARRIER()
+
+ if (v > SUBCARRIER_DETECT_THRESHOLD) {
+ // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
+ // note: synchronization time > 80 1/fs
+ Demod.sumI += ci;
+ Demod.sumQ += cq;
+ ++Demod.posCount;
+ } else {
+ // subcarrier lost
+ Demod.state = DEMOD_UNSYNCD;
+ }
+ } else {
+ Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF;
+ }
+ break;
+
+ case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
+
+ MAKE_SOFT_DECISION()
+
+ //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
+ // logic '0' detected
+ if (v <= 0) {
+
+ Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
+
+ // start of SOF sequence
+ Demod.posCount = 0;
+ } else {
+ // maximum length of TR1 = 200 1/fs
+ if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD;
+ }
+ ++Demod.posCount;
+ break;
+
+ case DEMOD_GOT_FALLING_EDGE_OF_SOF:
+ ++Demod.posCount;
+
+ MAKE_SOFT_DECISION()
+
+ if(v > 0) {
+ // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
+ if(Demod.posCount < 10*2) {
+ Demod.state = DEMOD_UNSYNCD;
+ } else {
+ LED_C_ON(); // Got SOF
+ Demod.state = DEMOD_AWAITING_START_BIT;
+ Demod.posCount = 0;
+ Demod.len = 0;
+ }
+ } else {
+ // low phase of SOF too long (> 12 etu)
+ if(Demod.posCount > 13*2) {
+ Demod.state = DEMOD_UNSYNCD;
+ LED_C_OFF();
+ }
+ }
+ break;
+
+ case DEMOD_AWAITING_START_BIT:
+ ++Demod.posCount;
+
+ MAKE_SOFT_DECISION()
+
+ if(v > 0) {
+ // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
+ if(Demod.posCount > 3*2) {
+ Demod.state = DEMOD_UNSYNCD;
+ LED_C_OFF();
+ }
+ } else {
+ // start bit detected
+ Demod.bitCount = 0;
+ Demod.posCount = 1; // this was the first half
+ Demod.thisBit = v;
+ Demod.shiftReg = 0;
+ Demod.state = DEMOD_RECEIVING_DATA;
+ }
+ break;
+
+ case DEMOD_RECEIVING_DATA:
+
+ MAKE_SOFT_DECISION()
+
+ if(Demod.posCount == 0) {
+ // first half of bit
+ Demod.thisBit = v;
+ Demod.posCount = 1;
+ } else {
+ // second half of bit
+ Demod.thisBit += v;
+ Demod.shiftReg >>= 1;
+ // logic '1'
+ if(Demod.thisBit > 0)
+ Demod.shiftReg |= 0x200;
+
+ ++Demod.bitCount;
+
+ if(Demod.bitCount == 10) {
+
+ uint16_t s = Demod.shiftReg;
+
+ if((s & 0x200) && !(s & 0x001)) {
+ // stop bit == '1', start bit == '0'
+ uint8_t b = (s >> 1);
+ Demod.output[Demod.len] = b;
+ ++Demod.len;
+ Demod.state = DEMOD_AWAITING_START_BIT;
+ } else {
+ Demod.state = DEMOD_UNSYNCD;
+ LED_C_OFF();
+
+ if(s == 0x000) {
+ // This is EOF (start, stop and all data bits == '0'
+ return TRUE;
+ }
+ }
+ }
+ Demod.posCount = 0;
+ }
+ break;
+
+ default:
+ Demod.state = DEMOD_UNSYNCD;
+ LED_C_OFF();
+ break;
+ }
+ return FALSE;
+}
+
+// Clear out the state of the "UART" that receives from the tag.
+static void DemodReset() {
+ Demod.len = 0;
+ Demod.state = DEMOD_UNSYNCD;
+ Demod.posCount = 0;
+ Demod.sumI = 0;
+ Demod.sumQ = 0;
+ Demod.bitCount = 0;
+ Demod.thisBit = 0;
+ Demod.shiftReg = 0;
+ memset(Demod.output, 0x00, 3);
+}
+
+static void DemodInit(uint8_t *data) {
+ Demod.output = data;
+ DemodReset();
+}
+
+/*
+ * Demodulate the samples we received from the tag, also log to tracebuffer
+ * quiet: set to 'TRUE' to disable debug output
+ */
+ #define LEGIC_DMA_BUFFER_SIZE 256
+static void GetSamplesForLegicDemod(int n, bool quiet)
+{
+ int max = 0;
+ bool gotFrame = FALSE;
+ int lastRxCounter = LEGIC_DMA_BUFFER_SIZE;
+ int ci, cq, samples = 0;
+
+ BigBuf_free();
+
+ // And put the FPGA in the appropriate mode
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_QUARTER_FREQ);
+
+ // The response (tag -> reader) that we're receiving.
+ // Set up the demodulator for tag -> reader responses.
+ DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
+
+ // The DMA buffer, used to stream samples from the FPGA
+ int8_t *dmaBuf = (int8_t*) BigBuf_malloc(LEGIC_DMA_BUFFER_SIZE);
+ int8_t *upTo = dmaBuf;
+
+ // Setup and start DMA.
+ if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, LEGIC_DMA_BUFFER_SIZE) ){
+ if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
+ return;
+ }
+
+ // Signal field is ON with the appropriate LED:
+ LED_D_ON();
+ for(;;) {
+ int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
+ if(behindBy > max) max = behindBy;
+
+ while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (LEGIC_DMA_BUFFER_SIZE-1)) > 2) {
+ ci = upTo[0];
+ cq = upTo[1];
+ upTo += 2;
+ if(upTo >= dmaBuf + LEGIC_DMA_BUFFER_SIZE) {
+ upTo = dmaBuf;
+ AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = LEGIC_DMA_BUFFER_SIZE;
+ }
+ lastRxCounter -= 2;
+ if(lastRxCounter <= 0)
+ lastRxCounter = LEGIC_DMA_BUFFER_SIZE;
+
+ samples += 2;
+
+ gotFrame = HandleLegicSamplesDemod(ci , cq );
+ if ( gotFrame )
+ break;
+ }
+
+ if(samples > n || gotFrame)
+ break;
+ }
+
+ FpgaDisableSscDma();
+
+ if (!quiet && Demod.len == 0) {
+ Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
+ max,
+ samples,
+ gotFrame,
+ Demod.len,
+ Demod.sumI,
+ Demod.sumQ
+ );
+ }
+
+ //Tracing
+ if (Demod.len > 0) {
+ uint8_t parity[MAX_PARITY_SIZE] = {0x00};
+ LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE);
+ }
+}
+//-----------------------------------------------------------------------------
+// Transmit the command (to the tag) that was placed in ToSend[].
+//-----------------------------------------------------------------------------
+static void TransmitForLegic(void)
+{
+ int c;
+
+ FpgaSetupSsc();
+
+ while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))
+ AT91C_BASE_SSC->SSC_THR = 0xff;
+
+ // Signal field is ON with the appropriate Red LED
+ LED_D_ON();
+
+ // Signal we are transmitting with the Green LED
+ LED_B_ON();
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
+
+ for(c = 0; c < 10;) {
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+ AT91C_BASE_SSC->SSC_THR = 0xff;
+ c++;
+ }
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+ volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
+ (void)r;
+ }
+ WDT_HIT();
+ }
+
+ c = 0;
+ for(;;) {
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+ AT91C_BASE_SSC->SSC_THR = ToSend[c];
+ legic_prng_forward(1); // forward the lfsr
+ c++;
+ if(c >= ToSendMax) {
+ break;
+ }
+ }
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+ volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
+ (void)r;
+ }
+ WDT_HIT();
+ }
+ LED_B_OFF();
+}
+
+
+//-----------------------------------------------------------------------------
+// Code a layer 2 command (string of octets, including CRC) into ToSend[],
+// so that it is ready to transmit to the tag using TransmitForLegic().
+//-----------------------------------------------------------------------------
+static void CodeLegicBitsAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits)
+{
+ int i, j;
+ uint8_t b;
+
+ ToSendReset();
+
+ // Send SOF
+ for(i = 0; i < 7; i++)
+ ToSendStuffBit(1);
+
+
+ for(i = 0; i < cmdlen; i++) {
+ // Start bit
+ ToSendStuffBit(0);
+
+ // Data bits
+ b = cmd[i];
+ for(j = 0; j < bits; j++) {
+ if(b & 1) {
+ ToSendStuffBit(1);
+ } else {
+ ToSendStuffBit(0);
+ }
+ b >>= 1;
+ }
+ }
+
+ // Convert from last character reference to length
+ ++ToSendMax;
+}
+
+/**
+ Convenience function to encode, transmit and trace Legic comms
+ **/
+static void CodeAndTransmitLegicAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits)
+{
+ CodeLegicBitsAsReader(cmd, cmdlen, bits);
+ TransmitForLegic();
+ if (tracing) {
+ uint8_t parity[1] = {0x00};
+ LogTrace(cmd, cmdlen, 0, 0, parity, TRUE);
+ }
+}
+
+int ice_legic_select_card()
+{
+ //int cmd_size=0, card_size=0;
+ uint8_t wakeup[] = { 0x7F };
+ uint8_t getid[] = {0x19};
+
+ //legic_prng_init(SESSION_IV);
+
+ // first, wake up the tag, 7bits
+ CodeAndTransmitLegicAsReader(wakeup, sizeof(wakeup), 7);
+
+ GetSamplesForLegicDemod(1000, TRUE);
+
+ //frame_receiveAsReader(¤t_frame, 6, 1);
+
+ legic_prng_forward(1); /* we wait anyways */
+
+ //while(timer->TC_CV < 387) ; /* ~ 258us */
+ //frame_sendAsReader(0x19, 6);
+ CodeAndTransmitLegicAsReader(getid, sizeof(getid), 8);
+ GetSamplesForLegicDemod(1000, TRUE);
+
+ //if (Demod.len < 14) return 2;
+ Dbprintf("CARD TYPE: %02x LEN: %d", Demod.output[0], Demod.len);
+
+ switch(Demod.output[0]) {
+ case 0x1d:
+ DbpString("MIM 256 card found");
+ // cmd_size = 9;
+ // card_size = 256;
+ break;
+ case 0x3d:
+ DbpString("MIM 1024 card found");
+ // cmd_size = 11;
+ // card_size = 1024;
+ break;
+ default:
+ return -1;
+ }
+
+ // if(bytes == -1)
+ // bytes = card_size;
+
+ // if(bytes + offset >= card_size)
+ // bytes = card_size - offset;
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+ set_tracing(FALSE);
+ return 1;
+}
+
+// Set up LEGIC communication
+void ice_legic_setup() {
+
+ // standard things.
+ FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+ BigBuf_free(); BigBuf_Clear_ext(false);
+ clear_trace();
+ set_tracing(TRUE);
+ DemodReset();
+ UartReset();
+
+ // Set up the synchronous serial port
+ FpgaSetupSsc();
+
+ // connect Demodulated Signal to ADC:
+ SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+
+ // Signal field is on with the appropriate LED
+ LED_D_ON();
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
+ SpinDelay(20);
+ // Start the timer
+ //StartCountSspClk();
+
+ // initalize CRC
+ crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
+
+ // initalize prng
+ legic_prng_init(0);
+}
\ No newline at end of file
projects / proxmark3-svn / blobdiff